1. Field of the Invention
The present invention relates to a method for preparing hydroxyvitamin D compounds using microorganisms.
2. Description of the Prior Art
It is very difficult to directly introduce hydroxyl groups into vitamin D compounds at the 1.alpha.- and/or 25-positions by the method of organic synthesis, and such introduction has not yet been reported.
Furthermore, any methods of enzymatic chemistry for introducing directly hydroxyl group into vitamin D compounds using microorganism have not yet been reported, either.
It was possible in the past to directly introduce hydroxyl groups into vitamin D compounds at the 1.alpha.- and/or 25-positions by the method of enzymatic chemistry using animal organs. Namely, there were known the methods for introducing directly a hydroxyl group at the 1.alpha.-position using the homogenate or mitochondoria fractions of kidney of animals such as chicken [Nature, vol. 230, p. 228 (1971), J. Biolog. Chem. vol. 247, p. 7528 (1972), and Biochemistry, vol. 25, p. 5512 (1986)]. In addition, there were known the methods for introducing directly a hydroxyl group at the 25-position by perfusing a solution containing vitamin D compound with liver collected from animals such as rats [J. Clin. Invest., vol. 48, p. 2032 (1969), and Biochem. Biophys. Res. Commun., vol. 66, p. 632 (1975)] or using the homogenate of liver of animals such as rats [Biochem. Biophys. Res. Commun., vol. 36, p. 251 (1969)].
However, the methods of enzymatic chemistry using animal organs require a large amount of kidney or liver tissue, and the preparation of such organs is very time-consuming. Accordingly, these methods are ineffective and unpractical.